“I picked this up again because every time I enter a really old building with a spiral staircase I remember this quote from this exact book about why spiral staircases spiral clockwise, and I don't know if it's true or apocryphal or just plain fiction -- I suppose I could look it up -- but I just love that it's permanently engrained in my memory at this point:

"That stairway would be a narrow spiral, set to the left-hand side and twisting the right as it ascended. In that way, a right-handed swordsman climbing the stairs would be at a disadvantage to a right-handed defender. An attacker would have to expose all of his body in order to use his sword, while the defender could strike with only his right side exposed. It was standard design for the castle tower.”